Telephone system with instantaneous disconnect and recall.



T. J. TUNE.

TELEPHONE SYSTEM WITH INSTANTANEOUS DISGONNECT AND RECALL. APPLICATION FILED 061. I0. 1914.

. Patented Aug. 27, 1918.

[271/"5277527 T1555 LZ-TLZZYE UNITED THOMAS J. TUNE, OF CLEVELAND, OHIO, ASSIGNOR TO KELLOGG SWITCHBOARD 8E SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE SYSTEM WITH INSTANTANEOUS DISCONNECT AND RECALL.

Specification of Letters Patent.

Patented Au. 2?, 1918.

Application filed October 10, 1914. Serial No. 865,983.

To all whom it may concern:

Be it known that I, THOMAS J. TUNE, a citizen of the United States of America, residing in Cleveland, county of Cuyahoga, State of Ohio, have invented certain new and useful Improvements in Telephone Systems with Instantaneous Disconnects and Recalls, of which the following is a specification.

My invention pertains to telephone systems having operators cord circuits employing instantaneous disconnect circuits, anc has to do more particularly with the pro vision of control circuits whereby she may again operatively associate the cord circuit with a line over which a recall has been initiated and also associate her telephone with the cord.

In certain systems of the above character cord circuits are so arranged that subscriber by replacing his receiver upon its switch-hook, while the cord circuit is con nected with his line, effects instantaneous disconnection of the cord conductors from his line so that a subsequent removal of the receiver will again light his line lamp to indicate a recall even though the cord circuit is still connected with his line. In systems of this character wherein automatic listening is provided, that is the automatic connection and disconnection of the operators telephone by the insertion of the answering and calling plugs, should a subscriber attempt a recall the operator must remove one or both plugs from their connected jacks before she can converse with the subscriber who has initiated such recall. In order to obviate such disconnection o the plugs responsive to a recall, I provide an operators key controlled circuit Whereby when a cord circuit is operatively disassociated from a line and a recall initiated, the actuation of such key will operatively connect the cord circuit to the recalling line and conductively unite its ends, at the same time connecting hertelephone set with the talking conductors of the cord so that she can converse with the recalling subscriber.

In the accompanying drawing, have illustrated the preferred embodiment of my invention, andIhave shown two substations A and C terminating in line circuits L and L adapted for interconnection by an opertip relay ators cord circuit B. The line circuits are of a well-known two-wire type including line and cut-0E relays. The cord circuit is also of a well-known type and comprises an answering sleeve relay AS, an answering AT, a calling sleeve relay CS, and a calling tip relay CT. I also provide a link disconnect relay LD which is energized to operatively disconnect the link circuit from a connected calling line when the subscriber at the substation replaces his receiver. A recall key RE is also provide which the operator actuates upon receiving a recall signal whereby the link disconnect relay LD is restored and the operators telephone 0 connected to the talking conductors of the cord.

I also provide automatic connecting and disconnecting means for the operators tele phone, including contacts on the answering and calling sleeve relays.

A register device for recording calls is also provided and includes meter relay MR- and meter magnet MM which are operated through contacts of the answering tip relay when a call is answered.

Automatic ringing apparatus is also provided comprising a well-known type of harmoni ringing controlled by a ringing key RIC, a ringing control relay BC and an interrupter relay IR. The ringing key includes four ringing contacts and a common contact 1 which is adapted to be closed only while the ringing plungers are in a fully actuated position. When the ringing plunger returns to its intermediate or indicating position, the ringing contacts remain closed, but the common contact 1 is again opened. The operation of the ringing key locks the ringing control relay BC in its energized position whereby the interrupter relay IR is operated to intermittently apply ringing current to the called line. /Vhen a sub scriber responds, the calling tip relay is energized causing the restoration of the ringing control relay hich renders the interrupter relay IR inert. I also provide ringing indicating means in the form of a winding :2 preferably of few turns upon the answering tip relay which winding is included in the ringing circuit so that its inductive effect upon the main winding of the answering tip relay will apprise the calling subscriber of the fact that the called. line is being rung.

Operation.

Having described in apparatus employed in my invention as illustrated, its operation in establishing a connection between substations A and will now be described more in detail. To initiate a call the subscriber at substation it removes his receiver establishing an energizing circuit for the line relay LR and lighting the line lamp The operator in response to this signal inserts the answering plug AP into the answering jack of the calling line whereby relays CO and AS are connected in series causing the energization of both. The operation of CO connects the answering jacl: to the calling line and restores the line a general way the relay and thereafter the answering tip relay AT energized by current flowing from battery through the winding of AS over the calling line and returning through the winding of AT to ground. The closing of alternate contact l of relay AT operates the call meter and the closing oi alternate contacts 5, (3 of relay AS connects the operator's telephone 0 through normal contacts 7, 8 to the talking conductors of the cord.

The operator now ascertains the number oi: the wanted substation and upon testing the wanted line in the usual manner, and finding it idle inserts the calling plug Cl into a jack thereof. This act connects the calling sleeve relay CS and cut-oil relay CO in series causing the euergization of both. The closing of alternate contact 9 or relay CS establishes a circuit for the calling super 'isory lamp signal CL through normal contacts 10 and 11. The interruption of normal contacts 7, S disconnects the operators telephone, thereby giving automatic disconnection.

The operator now depresses the proper ringing plunger, thereby momentarily clos mg the common contacts 1 of the ringing key whereby a circuit for the ringing control relay RC is established traced from battery through the winding thereof. contacts l to ground at alternate contact 9. Relay RC therefore energizes interrupting the talking conductors at normal contacts 12 and 13, and the closing of alternate contact l4. establishes an operating circuit for the interrupter relay R. The interruption oi normal contact 11 of relay RC etlaces the calling supervisory or clearing out signal C i and the closing of alternate contact 11 lights the ringing lamp BL. The initial energizing circuit for @C being only of momentary duration through contact 1. a locking circuit for this relay is provided traced back over conductor 15, normal contact 16, alternate contact 11" normal contact 10 and alternate contact 9 to ground. The

ringing current from the connected gencra tor traverses a path including alternate con tact 1S tip conductor of the cord returning over the connected line, part flowing through relay CS and part through alternate contact 13 and the signal back winding Due to the inductive effect of the ringing current through winding 2 upon the energizing winding of relay AT, the calling subscriber receives an indication that ringing current is being applied to a called line.

Upon response of the called subscriber and the first following deenergization of relay ill, a circuit for the calling tip relay CT is established through normal contact 18 so that rela CT is energized by current h owing throi'igh CS Relay CT therefore interrupts its normal contact. 10, and as this contact is included in the circuits of relay BC and ringing lamp EL they are rendered inert. Upon restora tion of relay BC the talking conductors of the cord are rendered continuous and the interruption of alternate contact 14 prevents further operations of the interrupter relay Ill. The interruption of alternate contact 13 of RC disconnects the signal back winc iug 2.

Upon completing conversation and suming the subscribers desire disconnection, they replace their receivers upon their respective switch-hooks, interrupting the circuits tor tip relays AT and CT. The en; suing deenergization of CT establishes a circuit for the supervisory lamp CL and the deenergization of relav AT establishes a circuit for the answering supervisory lamp AL. The circuit for AL may be traced from 1 atterv through the lamp, normal contact 20, alternate contact 21, toground at alternate contact 9. This ground connection to normal contact: QO also establishes a circuit for the link disconnect relay LD whereupon it is energized interrupting normal contacts 22, to operatively disassociate the link talking conductors from the calling line and the sleeve relay AS is maintained energized through alternate contacts 25, 21 and 9 to ground. As above stated, it has been assumed that the subscribers replaced their receivers for disconnection, in which case the operator observing the lighting of the supervisory lamps AL and CL withdraws the plugs from their respective jacks. The relay CS therefore is restored interrupting the alternate contact 9 which has been main taining relays LD and AS energized and lamps All and CL lighted, so that these four elements are restored to normal.

rissuming now that a connection had been established between substations A and C and upon finishing conversation, the subscriber at A initiates a recall by again removing his receiver prior to the withdrawal of the plugs from their acks.

and over the called line.

It will be remembered'that when the subscribers at'stations A and'C replace their receivers, disconnect relay LD was operated to disconnect the link conductors from the line of substation 'A. This of course results in the restoration of the cut-off relay 00 so that the'subscriberat A upon again removing his receiver before the plug AP has been withdrawn, effects the lighting of his line lamp 3. Although the operator has received a disconnect signal by the operation of lamps AL and CL, she also observes that the lamp 3 associated with the answering jack in which plug AP is inserted, has been lighted, and knows that her attention is desired. Therefore, it is not necessary that she withdraw either of the plugs from their connected acks'in order to beable to again connect her telephone to the cord circuit, but she need only actuate the recall key RE. This interrupts the circuit for the link disconnects relay LD whereupon it restores and operatively connects the link talking conductors to the recalling line. As before, this act causes relays AS, CO and AT to be energized, and the closing of alternate contacts 27, 28 of the recall key connects the operators telephone to the cord talking conductors so that her telephone set is operatively associated with both ends of the cord and she may converse with the calling subscriber to ascertain his Wants.

From the above, it will be seen that when a recall is initiated and bothplugs remain in connection with line jacks, although the original listening circuit is not effective on account of the interrupt-ion of contacts 7, S, of relay CS, the operator by the actuation of her recall key, unites her telephone with both ends of the cord circuit without'having to remove either plug from the jack.

Having described my invention what I claim as new and desire to secure by Letters Patent is: I

1. A telephone system comprising telephone lines, an operators cord circuit for connecting calling and called lines, an operators telephone, automatic means for connecting and disconnecting said operators telephone and said cord circuit, cord disconnect means responsive to the replacing of the receiver of a connected line upon its switch-hook, and operator key controlled circuits for reconnecting the cord to the last said line and connecting the operators telephone to the cord without the removal 0 either plug from its connetced jack.

2. A telephone system comprising telephone lines, an operators cord circuit for connecting calling and called lines, an operators telephone, automatic means for con necting and disconnecting said o-perators telephone and said cord circuit, cord disconnect means responsive to the replacing of the receiver of a connected line upon its switchhook, an operators key, and'control circuits for reconnecting the cord to the last said line and connecting the 'operators telephone with the cord without the removal of either plug from its connected jack.

3.A telephone system comprising telephone lines, an operators cord circuit, an operators telephone, means responsive to the insertion of the answering and calling plugs into the jacks of telephone lines for automatically connecting and disconnecting the operators telephone, cord disconnect means" responsive to the replacing of the receiver of a connected line upon itsswitehhook, and operator key controlled circuits for reconnecting the p and connecting the operators'telephoneto the cord without the removal of either plug from its connected jack.

4:. A telephone system comprising telephone lines, an'operators cord circuit, an operators telephone,means responsive to the insertion of the answering and calling plugs into the jacks of telephone lines for automatically connecting and disconnecting the operators telephone, cord disconnect means responsive to the replacing of the receiver of aconnected line upon its switchhook, an operators key, and circuits controlled thereby, for reconnecting the cord to the last said line and connecting the operators telephone to the cord without the removal of either plug from its connected jack.

A telephone system comprising telephone lines, an operators cord circuit for connecting calling and called lines, an operators telephone electromagnetically controlled means for connecting and disconnecting said operators telephone andsaid cord circuit, means responsive to the replacing of the receiver of a connected line upon its switchhook for conductively disuniting the opposite ends of the cord and operatively disassociating said cord from said line, and operator key controlled circuits for conductively uniting the opposite'ends of the cord to said lines, and connecting the operators telephone to the cord without the removal of either plug from its connected jack.

6. A telephone phone lines, line signals for said lines, an operators cord circuit, an operators telephone, electromagnetically controlled means for connecting and erators telephone and said cord circuit, means responsive to the replacing of the receiver of a connected line upon its switchhook for operatively disassociatiug said cord and line, means responsive to a subsequent removal of .the cord is still connected thereto for opthe receiver of said line while crating its line signa, and operator key controlled circuits for operatively associating the cord' and-the said line and connect-- ing the operators' telephone to the cord cord to said last line a system comprising tele disconnecting said opllil disassociating his line without the removal of connectedjack.

7. A telephone system comprising subscribers lines, a link circuit folconnecting said lines in conversational circuit, an answering superiiisory signal, means associated with said link circuit responsive to subscriber control to operatiyely disassociate said link circuit from one of said subscribers lines and'to actuate said supervisory signal When said subscriber signals for disconnection, an operatorls key, circuit connections controlled by said key for again associating said subscribers line with the said link circuit When said subscriber signals for a recall and a relay energizable over the subscribers line for efi 'acing said supereither plug from its ,yisory signal.

8. A "telephone system comprising subscribers lines, a link circuit forconnecting said lines, an operatorlstelephone, automatic means for connecting and disconnecting the said operators vtelephone and said link circuit, subscriber controlled means for dis associating said link circuit from one of said subscribers lines, an operators key, and circuit connections controlled thereby for reconnecting the operators telephone With the saidlink circuit and for reassociating the said linkcircuit with the subscribers line.

9. A telephone system including subscribers lines, a link circuit foroonnecting said lines, an answering supervisory signal, a relay associated with said link circuit adapted to be energized responsive to a control exercised over one of said subscribers lines for operatively disassociating the said connected subscribers line. train the link circuit and for actuating said superyisory signal, anoperators key for said linkcircuit, and a circuit for said relay adapted to be opened by said :key to restore said relay, whereby the said link circuit is again asso ciated with said subscribers line.

10. A telephone system comprising subscribers ines,an operators link circuit for interconnecting the said lines, an operators telephone, automatic means for connecting and discom'iecting said operator s "telephone and said link circuit, means under tl1e1control of a connected subscriber foroperatiyely from said link cirsaid link circuit, and circuitconnections controlled by said my for reconnecting said link circuit With said subscribers line and for reconnecting said operators telephonewith said link circuit.

11. A telephone system comprising sub scribers lines, an operators link circuit for interconnecting the said lines, an operators telephone, automatic means for connecting and disconnecting said opera-tors telephone and said link circuit, means under the cuit, an operators key for con- IOl Of a CQl lll ecte dSubscrib fo y p i y an operators key for energizing scribersflines, a link circuit for disassociatinghis line from said link circuit, said link circuit, and c rcuit connections controlled by said key for reassociating said link circuit with said subscribers line and for connecting said onerators telephone with said link circuit Without remoying the link circuit plugs from the subscribers line jacks.

l2. A. telephone system comprising sub scribers lines, a link circuit forconnecting said lines in conversational circuit, a relay associated With said link circuit energizable respousii e to. subscriber tively disassociate said linkcircuit from one of said subscribers lines When disconnection is signaled for an operator's telephone, an operators key, and circuit connections controlled said key for again associating said line With the said link circuitby de said relay when said subscriber signals for a recall prior to the removal of either of the link plugs irom their connected jacks and for connecting said operatofs telephone With said link circuit.

13.;A' telepnoue system comprising subscribers lines, a link circuit for connecting said lines, an operator's telephone, auto matic means iorconnecting and disconnecting the said operators telephone and said link circuit, subscril'ier controlled means for disassociating said link circuit from one of said subscribers lines, an operators key, and circuit coin'iections controlled thereby for reconnecting the operators telephone with the link circuit and for roassociating the link circuit with said subscribefis line, Without the remoyal'of either of the link circuit' plugs from its connected jack.

14. A telephone systein including subconnecting said lines,'a rolayassociated with said link circuit and under substation control for operatively disassoriating a connected subscribers line from the link circuit, an operators key for said link circuit, and a circuit for said relay controllable bysaid key and adapted to be opened when said key is operated to dcenergize the same thereby again connecting'said 'link circuit to said subscribers line.

15. A telephone system comprising sub scribers telephone lines, a manual link circuit for connecting two of said lines in a con ersz'itional circuit, an opera ions telephone, automatic means responsiye to connection oi said link circuit a calling and a called one of said lines respectively for connecting and disconnecting the said operatofls telephone and the said link circuit, electromagnetic o ins controlled at the substation or one of the connected linestor operative y ,disasso'ca t" 1g said connected line from said link circui and for restoring the subscribers linecircuit equipment to normal, an operators key for said link circuit,

and circuit connections controlled by said key for reconnecting said opcrators telephone uith said linkcircuit and for reassociating scribers line without necessitating the removal oi the link circuit plugs from the line jacks ot the connected lines.

16, A, telephone system including subscribers telephone lines, a cord; circuit provided with terminals fonconnecting said lines in conversational circuit, an operators telephone, means responsive to connection of the said terminals with a calling and called one of said lines for automatically coimccting and disconnecting said operators telephone and said link circuit, means associated with said link circuit and con trollable from the substation of the calling line for disassociating said link circuit from said callingsubscribers line when said calling subscriber signals for disconnection, and a key for said link circuit, said key being operable by a central ofiice operator to cause said operators telephone to be reconnected to said link circuit and to reassociate said link circuit with said calling subscribers line.

17. A telephone system comprising subscribers telephone lines, a link circuit provided with connection terminals for connecting said lines in conversational circuit, inductive devices normally connected to the strands of said link circuit and to said terminals, subscriber-controlled means associated with said link circuit for opcratively disassociating said inductive devices from a connected one of the subscribers lines, an operators key and circuit connections controlled by said key for again associating said inductive devices with said subscribers line prior to the disconnection of said connection terminals from said lines.

18.. In a telephone system, the combination of a subscribers line connected with a. plug-ended link circuit, of an inductive device for said link circuit to which said plug is normally connected, subscriber-controlled means for disassociating said inductive device from said subscribers line, an operators telephone, an operators key, and circuit connections controlled by said key tor again associating said inductive device with said subscribers line and for connecting said operators telephone to said subscribers line.

19. A telephone system comprising subscribers lines, a. link circuit provided with connection terminals for connecting said lines in conversational circuit, a battery supply relay normally connected with a strand of said link circuit for supplying talking current to one of said connected lines, means associated withsaid link circuit responsive to subscribers control to operatively disconnect said battery supply relay from said said 7 link ,eircuit with said sub subscribers telephone line, an operators key, and circuit connections controlled thereby for againconnecting said battery supply relay to said subscribers line without disconnecting said connection terminals from said subscribers lines. 7 y

20.111 a telephone system, the combination of a link circuitconnected to a subscribers telephone line, of a battery supply reh y normally connected to a. conductor of said link circuit, means controlled solely over said subscribers line for disconnecting said battery supply relay from said subscribersli'ne, an operators key, and circuit connection controlled thereby for reconnectingf said battery supply relay with said subscribers line. 7

2.1.In'a telephone system, a subscribers telephone line connected with a plug-ended operators link circuit, a battery supplyrelav normally connected with a contact of said plug, substation controlled means for disconnecting said battery supply relay from said plug, an operators listening key, and means controlled by said key for reconnecting said battery supply relay with said lug.

22; A telephone system including a pair of subscribers telephone lines, a link circuit provided with connection terminals for connecting said lines in conversational circuit, a relay for said link circuit for disconnecting one of the connected subscribers lines from the said link circuit, a relay for said link circuit controllable over the said subscribers line for energizing the said first relay, and a key for said link circuit for deenergizing the said first relay to again connect the subscribers line with the link circuit prior to the disconnection of said connection terminals from said subscribers lines.

23. A telephone system including a calling subscribers telephone line, a link circuit provided With a connection terminal for connection therewith, a battery supply relay for said link circuit normally connected to said connection terminal, a relay for said link circuit controllable over said calling subscribers line for disconnecting said battery supply relay from said subscribers line, and a key for said link circuit controllable by a central ofiice operator for deenergizing said disconnect relay to again connect said subscribers line to said battery supply relay prior to the disconnection of said connection terminal from said subscriber-"s line.

24. A telephone system including a pair of subscribers"telephone lines, a link circuit provided with connection terminals for connecting said lines in conversational. circuit, a relay for said link circuit for disconnecting one of the connected subscribers lines from the said link circuit, a relay for said link circuit controllable over the said connected subscribefls line for-energizing the said first relay and a key for said link cil 'cuit foi deenergizlng said first relay to again connect the subscribefs line With said link oil'- cuit.

25. A telephone system including' a subscribets telephone line connected With a plug-ended operators link circuit, a battery supply relay normally connected to said plug, means for di connecting said battery supply relay from said plu substation controlled means for operating sa id first nieans, an operators listening key, and means controlled by said operators listening key for operating said first means to reconnect said battery supply relay to said plug.

26. A. telephone system including a call ing and a calledsubscribefis telephone line,

@epfiei: ofthia patent may be obtained fol-five; cents each, adfireQtnEtM @ofiimtsslonex of Patents, Washington, G. 

